The Foshuo shieryou jing may be called a small biography of the Buddha. It begins with the origins of the Sākya clan, speaks of Sakyamuni's observations of society, his birth, and his family (parents, relations, wife), and describes the twelve years after his enlightenment. This article points out that it is possible to interpret the descriptions given of those twelve years as indicating the location of twelve of Sakyamuni's rainy season retreats, and it discusses the relationship between these and other traditions concerning the location of the retreats. At the same time, it also attempts to identify the sources used in the compilation of the Foshuo shieryou jing. Because it was quoted widely in Mahayana sutras, it is easy to understand that it was based on Mahayana scriptures, but a reappraisal about whether or not it has any connection with the early Buddhist sources confirms that it was not connected in any way with them.